Reinforced fibrous board and process of producing the same



T. B. MUNRUE. y l BEINFORCED FIBROUS BOARD AND PROCESS OF PRODUCING THE SAME.

`APPLICATION FILED APR. 3, 1919.. I I

Patented Apr. 6, 1920.

TEM un, 110e A To all'whom 'it may concern:

UNITED sTATEs PATENT' OFFICE. 1

'.rREADvenn' B. MUNRoE, or FoREsT GLEN, MARYLAND, AssIGNoR T'oB. G. DAHLEERG,

- 0E sT. PAUL, MINNEsoTA.- 1 l REINEORGED EIBRoUs BOARD AND rRocEss or PRoDUcING THE SAME.

Application med Aprire, 1919. s erial Ng.V 23,139( y l p Be it known that I, TREADWAE B. MUN- ROE, a citizen ofthe United States, residing at Forest Glen, in the county of Montgomery and State of Maryland, have invented certain new and useful Improvements in Rein-v forced Fibrous Board and Processes of Producing the Same; and I do hereby declare the following to be a full, clear,'and exact description ofthe invention, such as w1lly enable others skilled in the art to whichl it appertains to make and use the same.

This invention relates to reinforced fiber' board material and process of producing the same, and has for its object to provide an article which will be more efficient in use, and a method which will be more simple and easy to lcarry out than those which have'beeIi heretofore proposed.

With these and other objects in view the invention consists in the novel structure of the article and in the novel steps and combi- Figure 1 is a diagrammatic sectional Viewy of a portion of an apparatus suitable for carrying out the present process;

Fig. 2 is a plan viewpartlally broken away of a portion of the material made in accordance with this invention;

Fig. 3 is a sectional view of the material shown in Fig. 2;

Fig. 4 1s an enlarged diagrammatic view illustrating the disposition of the fibers during the process of making the articles; and- Fig, 5 is a sectional View of a slightly modified form of interior construction of the article.

1 indicates any suitable tank or container adapted to hold water or other liquid carrying the cellulose pulp material out of which the article is made, 2 any suitable traveling belt adapted to exert a predetermined pressure upon the pulp material after it is formed into aboard like mass, and 8 any suitable drum or roller provided with a foraminous surface such as 4, and adapted to coact with the belt A2 in compressing the fibers to a sheet of predetermined thickness. f5 'represents'any reinforcing material such fdiyexample as Iwire cloth or'fther suitable 'fabric which is ,convenientlyfsp porte Vhe form of a roll 6, and feidfdown under rollerj? y'lol'cateldin thetank led out between "the roller 9 carr' beltl2, and the Iupp -rrk surface of the drurn- 3 'as illustrated" Th' lt-2 passes around the guiding muet fof dltdgetherwith thefammsis give-1i' 'ma nie'a'ns, such-"as the belt 8. l

The cellulose fiber material, out of which Ithe linslilfti111g board constituting" this invent1on`1s made, vdiffers essentially from the' sliver like fibers is a third vclass of hair' like' with the ordinary comparatively short and.

-very fine fibers used in paper making.

These several classes of fibers. are mixed to a suitable consistency in water preferably in the, proportions of from less than 1 to 5 parts of fiber to 99 or more to 95 parts of water, and are fed down into the tank 1 from the well 30 in which the water level is maintained high enough to provide a suiiicient pressure to force the mixture up through the reinforcing material 5 which catches some of the fibers, while others which'pass'through the openings in the said material 5 continue upto the traveling belt 2 as indicated by the arrows 16 in Fig. 1.

. This said head or pressure lfurther forces i the water through the'interstices of the f'oraminous surface of the roller or drum 3 "iilith dirfionif fhaffows' and 12 lrespectively by. any-suitable Specification of Letters iatent.- Patented, Apr. 6, 19.20.; p

in F ig. 1, but the fibers which are carried bythe said water are substantially all caught v under side ofy the' foraminous material 5,`

by and deposited on the said belt 2 .and surface 4. The belt 2 and surface 4 being preferably made of wire cloth of say from 10 to 14 mesh, the fibers as they are impelled by -the stream of water in the direction of .the

arrows 18, felt or mass themselves againstl the under surface of the belt 2, and also'- against the outer surface 4 of the drum 3.

addition to this'more or less ofthe fibers coln lect in the restricted space 19 between the traveling wire cloths 2 and 4, -and are there entangled and interwoven with the fibers composing the felted sheet-like masses that collect on the surfaces of said cloths 2 and 4, thus producing a reinforced board in which the vfibers are thoroughly felted andpinterwoven throughout its entire thickness. the said cloths 2 and 4 continue to.move the entire mass is lightly compressed between the roller 9 and the drum 3 to expel some of the water, and the. board emerges at the point 20 containing from only 50% to 7 5% of water. l

-By locating the, foraminous reinforcing material 5, however, between the traveling cloths 2 and 4, as indicated, a large portion of said fibers are forced up through the meshes 22 of said foraminous material 5, see Fig. 4, and another portion 23 and 24 of said fibers is caught on each side of said material 5, all as will be clear from said figure. It results from this that a lpronounced interlacing, or felting action. takes place on the and a lesser interlacing, or felting action of the fibers takes place on the upper side of given, i. e. from 1 or less to 5 parts of fibersaid material, with the result that the said foraminou's material 5 is thoroughly felted into the mass or body portionof the final board 25 as is indicated in Figs. 2, 3 and 4. The said foraminous material 5 being thus firml of said-board and in fact gives the said board in a sense some of the properties of reinforced glass in thatthe said board may receive blows and other injuries without bein punctured or destroyed.

e proportions of fiber to water above to 99 or more to 95 parts of water arevery important, for they provide a stock mixture .r 'in whicheach individual fiber is completely suspended, which suspension results in 'thegreat majority of the fibers traveling lengthwise, much after the manner of a stick floating in a swiftly moving stream. This said endwisetravel of thefibers has been found to produce `a greatly improved felting action, for the ma'ority ofthe fibers strike the foraminous sur aces 2 and 4 at substantially right angles thereto, and. before they have a anchored on the interior of the .fiber boar v25, it adds very greatly to the strength chance to be flatteneddown upon said surfaces other fibers are deposited beside them,

whereupon the entire mass becomes more' intermingling and interweav'ing of the de` posited fibers.

In this connection it might be pointed out that the felting action utilized by the present'invention is sharply distinguished from the 'so called felting in paper making, wherein it is the constant endeavor to have the short, fine fibers there used lie flat against the foraminous belts or screens, with only su'fcient actual felting to give coherence to the sheet. In' the present case however, it is essential that the long'tliread like I fibers, the hair like fibers and the coarse sliver ylike fibers be all intimately interwoven, and felted throughout the entire thickness of the board,`the short, fine fibers being used merely asa filler, and to give the board a more finished surface.

The peculiar nature of the above mentioned classes of fibers 13, 14 and 15 lend themselves to the incorporation of the wire cloth 5 or other foraminous material, in that the differentoarsenesses of these said bers y cause the board 25 to' be unusually porous and this porosity greatly facilitates the felting action of the finer fibers between the coarser fibers so lthat the wires or threads constituting the foraminous material 5 find themselves filling. the interstices between the vfibers while the fibers themselves are so interwoven as to make a more or less homogeneous mass.

' Stated in other language, as is well known, cellulose fiber material made after the usual fashion of felting it is liable to form into more or less pronounced layers and when the board is subjected to hard usage, it is liable to Hake along the planes of these layers and thus to develop an undesirable weakness .in use. But owing to `the differences in coarseness of the various fibers, as well as to the large quantity ofwater used and its velocity through the appar-atus, as above explained, this particular board not only has its layers much less pronounced than would otherwise. be the case, but the strands of the wire cloth 5 serve to fill up to a greater or less degree the interstices between the individual fibers and thus bind the various layers together to a greater or less extent. This binding action is somewhat enhancedv in the modified, form of board illustratedin Fig. 5. 'In this gure the foraminous material 5 instead of being substantially in a single plane .as indicated in Fig. 3, is zig-zagged or built into different planes so that .a point such as 26 of said foraminous material will be located' in one plane of the board 25 while another point 27 ofsaid foraminous material will be lo` cated in an entirely different plane. The

strands joining the point 26 and 27 will pass 7 through aplurality of layers and 'thus' will more orv less rmly bind all thela ers together. After the reinforcing fabric 5 has.

been thus incorporated into the pulp like mass, and after the ,desired pressure has been exerted upon said mass by means of the rollers or drums 3- and 9, the wet felted material may be passed to aj suitable drying chamber or machine, dried out, cut into suitable lengths, or handled by other known methods as maybe desired.-

-The material may be easily waterproofed or reproofed to most any desired conditions o use, by introducing the waterproofing or reproong material in to the tank 1.

or other suitable apparatus not shown and v thoroughly mixing the-same with the bers or the mshed sheet may be coated on the -outside by any suitable means with the desired waterproofing or reproong material. For example, if it is. desired' to waterproof the board, a suitable 'proportion of vordinary rosin size, say 10% `may be added to the stock in the well'30, or at .other 'suitable place not shown and thoroughly mixed therewith. sulfate' may then be- .added to precipitate aluminum resinate and free rosin, which, due to the fact that each ber 'is completely suspended as above pointved out, coats each individual ber. with la waterproofing compound, the material is then felted as above described, and issues from the machine containing from 50% to 8,5% of water.

'It will of course be necessary to get rid of this surplus water before the board will be waterproofed and this may be done in any suitable manner, as Vfor example, by-

heating. In thisfstep, however,.care must be taken to dry -the board progressively fromthe interior outwardly, for if the 'outer portions are dried rst they become Waterproof, andit is thenimpossible to get the remaining water from the'interior portions.

To thisA end I prefer to dry the boards in a continuous drier preferably steam heated, in which the atmosphere is kept moist, so

' that the interior portions ofthe board. dry

rst. If this method of drying -iscontinued until the board contains not more than say 5% of water, a vproduct is obtained which is thoroughly waterproof, possesses a good surface and isof great structural strength. The-surface. obtained is lespeoughly is desired, the s'tck or the finished boards I `may be treated inv anysuitable manner to produce such a result. I, prefer, however, in this case to treat the material with a substance which is substantially insoluble in water, but which under the influence of-moderate temperature, say 150 C. to 500 C. willy solid, liquid or gaseous, 'one or more of which Abreak down into its constituent parts, either will not support combustion. Or, with a subgive olf an inert gas, incapable of supportmg combustion. For example, ber thoripregnated with A'ferrous -oxalate, FeC24.2 2O reproof. The .said ferrous oxalate, when raised to a temperature ofapproximately A160 C. decomposes into two molecules of Water, one molecule o f carbon dioxid CO2, one molecule of carbon monixid CO and one atom of iron. Of these, only' the carbon monoxidA will support combustion,"but

this is overcome by the preponderance ofl other gases,- liquids, and solids, produced which will not support combustion.

Further, if desired, instead of applying the ireproong material directly lto the ber, it may `be formed thereon by thereaction` of two or more substancescapable of producing it. For instance, instead of applying the ferrous oxalate directly, ferrous sulfate which is Water soluble may be mixed with the ber stock which -is then treated with oxalic acid to form he insolu ble ferrous oxalate.

It will of coursebe apparent that the board .may be produced without either the water# ystance whi'clnunder the influenceofheat,will

is found'to be substantially I' proongorifreproong; it maybe produced with the.v waterproong alone or with the roduced re roong alone; or it may be wit both the waterproofng'and reproofing all according to the use which is to be made of it. l f The board material 25; without the rein-vl forcing material 5 is so porous that it often does not possess a specific gravity higher thansay. .4`and often its specic gravity is much lower and in fact not higher than say 4 .2 so that it constitutes an excellent heat insulating material. On the other hand, if a -greaterdensity is desired the said material 25 may be lled'in any suitable manner with fa' dope or binder.

Again, should di'erent degrees of tenacity be desired in the nished product the woven 4 material may be discontinuously fed into the felted mass during the course of manufac- 'single mass; y

to remove a portion ofthe water contained -v ture or the woven material 5l itself may be made of different strengths at dierent portions of its length..

It is obvious'that those skilled in the art may varyvthe detailsof construction as well as the procedure for producing the ber scribed.

.2. The 1Lprocess of making a reinforced board of brous material which consists in felting a layerA of bers on a traveling foraminous surface; felting a second layer o f bers on a second vforaminous surface travelmg 1n thesame dlrection as said rst surface; felting a third layer of bers on a. reinforcing fabric travellng in the same di.

rection as said rst and secondnamed surlfacespand depositing other bers in the between said felted layers of bers spaces bers are felted together whereby all of said yinto a single mass, substantially as described.

3. The process of 'making a reinforced board of brous material which consists in felti'ng a layer of bers on a traveling` fOraminOuS-suraCe; felting a second layer of bers on a4 second foraminous surface, traveling in the same direction as said rst surface; yfelting a third layer of 'bers on a reinforcing fabric traveling in the samedirection yas said'rst and second named surfaces; depositing other bers in the spaces between said feltedlayers of bers whereby all of4 said bers are felted together into a compressing said mass lightly therein; suitably removing substantially all of the remaining water therefrom; and cutting the same into suitable lengths; substantially as described.

4. As a new article of manufacture a substantiallyej as deboard made of bers some of which are in the form of slivers, and having embedded in its main body portion areinforcing foraminous material with'a portion of the bers on each side of said material interlaced with each other through its interstices, substantially as described.

5. As a new article ofl manufacture p' a board composed of sliver like and ner bers and having a specic gravity notv higher than four tenths, said board also having embedded in its main body. portion a reinforcing foraminous Amaterial with a portion of the bers on each side thereof interlaced with each other through-its interstices, substantially as described.

.6. As a new .article of manufacture a board' composed of coarse sliver like and' ner bers 'and having a specific gravity not higher "than four tenths, said board also having embedded in its main body portion a reinforcing Woven foraminous wire cloth fabric with a portion of the bers on each side of said fabric felted together through its openings, substantially as described.

7. As a new article of manufacturel a board composed of coarse sliver like and ner bers and having a -specic gravity notv higher than four tenths, said boardv .having incorporated therewith a water'proong ma- Y terial and alsohaving .embedded in its main body portion, areinforcing woven foraminous wire cloth fabric with a portion of the bers on each-side of said fabric felted together through its openings; substantially as described.

A8. The process Iof making a porous fibrous 'board with a foraminous material embedded 1n its body which consists in oating a mass of sliver like bers mixed with other nerbers in water on eachvside of said yforami-l nous material while moving the latter; causing said water anda portion of said bers to pass in opposite directions throughthe o enings of said material to interlace some o the bers in said openings; and applyino` Dressure to the mass of bers on each side of said material to form the board, substantially as described.-

Intestlmony whereof I aix -my'signatura 'rREADWAY-B. MUNRoE. 

